F-Perm Madness

[cubersmith]

Okay, so I recently found this thing on a certain F-Perm:

R' U2 R' d' R' F' R2 U' R' U R' F R U' F

If that alg is performed on a solved cube, the switched pieces are in the left and the 1x1x3 block is on the right. This means that alg swaps pieces on the left.

This is where it gets interesting. After doing that alg, do a y' so that the swapped pieces are now in the front and the 1x1x3 block is in the back. If you perform the alg again, it now switches the pieces in the front, solving the cube.

I cannot understand how this happens. If anyone explains it to me I will be grateful.

Thanks.

 

[5BLD]

I think it's something to do with the d move.
Leme experiment... So I can come up with a less vague conclusion...

Edit: dargh... qq beat me to it.

 

[qqwref]

Performing the alg does a y rotation on the centers because of the d' move, and when you do a y' rotation you put the centers back in their original place. So the alg really swaps pieces on the front.

 

[Kirjava]

the alg swaps pieces on the front

add y' on the end of the alg and everything will make sense

edit; qqpwned

 

[cubersmith]

the alg swaps pieces on the front

add y' on the end of the alg and everything will make sense

edit; qqpwned

oh yeah.